ref: 5a2ad90bec85dbfd5c5f6bb1b0ff88a73cfe1911 dir: /sys/src/libc/386/argv0.s/
GLOBL argv0(SB), $4 GLOBL _tos(SB), $4 GLOBL _privates(SB), $4 GLOBL _nprivates(SB), $4